# -*- coding: utf-8 -*-
"""
Created on Tue Dec 19 16:18:06 2017
字典_数据结构:由键值对组成（键和对应的值，键是一个KEY,是不允许重复的，但是值可以重复），是无序的
@author: Administrator
"""
import pandas as pd

dict1 = {'Alice': '2341', 'Beth': '9102', 'Cecil': '3258'}
dict2 = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'}
print ("dict2['Name']: ", dict2['Name'])
print ("dict2['Age']: ", dict2['Age'])


dict2['Age']
dict2['Age'] = 10  #更新元素
dict2['school']='菜鸟教程'#增加元素
print ("dict2['Age']: ", dict2['Age'])
print ("dict2['school']: ", dict2['school'])
del dict2['Age']
dict.clear()  #清除键值对，保留字典
del dict2   #删除整个字典

dict2.update({'school':'middle'})
dict3 = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'}
dict3['school']= 'qujing'
len(dict3)
dict3['Name']
s='Name'
dict3[s]

#字典的初始化
d={}
s = [('Tom', 5), ('Jone', 2), ('Susan', 4), ('Tom', 4), ('Tom', 1)]

for i,j in s:
    d[i]=j
print(d)
for i in d.keys():
    print(i)

# 通过 Dataframe 创建，index 做为key，columns的值做为value
df_dict = df1['columns'].to_dict()
df_dict = df1.to_dict()


# 将字典保存到txt文件：
with open('dict3.txt','w') as f:
    f.write(str(dict3))
# 从txt文件读取字典：
with open('dict3.txt', 'r') as f:
    dict3 = eval(f.read())

dict3


# =============================================================================
# 进阶字典与map联合使用
# =============================================================================
df1 = pd.DataFrame({'name':['abc', 'def', 'ghi']})
df2 = pd.DataFrame()
df3 = pd.DataFrame()

dict1 = {'name':1,'def':2,'ghi':3}
dict2 = {1:'1st',2:'2nd',3:'3rd'}
df2['name'] = df1['name'].map(dict1)
df3['name'] = df2['name'].map(dict2)


#字典的迭代
# dict没有序号但也可以迭代：
d = {'a': 1, 'b': 2, 'c': 3}
for key in d:
    print(key)

# dict根据三种值进行迭代：
e = {'a': 1, 'b': 2, 'c': 3}
# iter each key:
print('iter key:', e)
for k in d.keys():
    print('key:', k)

# iter each value:
print('iter value:', e)
for k in d.values():
    print('value:', k)

# iter both key and value:
print('iter item:', e)
for k, v in d.items():
    print('item:', k, v)

# 默认情况下，dict迭代的是key。因为dict是无序的，所以，两次迭代出的结果顺序很可能不一样。
# 如果要迭代value，可以用for value in d.values()。
# 如果要同时迭代key和value，可以用for k, v in d.items()。


#字典的初始化
k={}
s = [('Tom', 5), ('Jone', 2), ('Susan', 4), ('Tom', 4), ('Tom', 1)]
for i,j in s:
    if i not in k.keys():#注意不能写成 if not k[i],因为其返回值不是None,而是error
        l=[]
        l.append(j)
        k[i]=l
    else:
        k[i].append(j)
print(k)


#字典的初始化
from collections import defaultdict
d=defaultdict(list)
s = [('Tom', 5), ('Jone', 2), ('Susan', 4), ('Tom', 4), ('Tom', 1)]
for i,j in s:
    d[i].append(j)
print(list(d.items()))

from collections import defaultdict
d=defaultdict(set)
s = [('Tom', 5), ('Jone', 2), ('Susan', 4), ('Tom', 4), ('Tom', 1)]
for i,j in s:
    d[i].add(j)
print(list(d.items()))

# 字典的初始化，一键多值的情况
dic4 = {}
key = 1
value_arr = [0,1,2,3,4]
value_arr1 = [5,6,7,8,9]
dic4.setdefault(key, []).append(value_arr)
dic4.setdefault(key, []).append(value_arr1)
print ( value_arr[4],' ',dic4[1][0][4])
print ( value_arr1[0],' ',dic4[1][1][0])

#字典的操作获取所有key
info = dict(name='cold', blog='linuxzen.com')
info.keys()
info.values()

x = list(info.values())
#获取key,value并循环
info = dict(name='cold', blog='linuxzen.com')
for key, value in info.items():
    print key, ':',  value